CORROSIVE WEAR BEHAVIOR OF 304-L STAINLESS-STEEL IN 1-N H2SO4 SOLUTION .1. EFFECT OF APPLIED POTENTIAL

The influence of applied potential on the corrosive wear rate of 304-L stainless in 1 N H2SO4 solution was studied using a modified pin-on-disc type wear machine. The corrosive wear rate increased with increasing applied potential up to 600 mV (vs. a saturated calomel electrode (SCE)), and then decreased. The corrosive wear rate W(cw) consists of three factors: pure mechanical wear loss W(MECH), weight loss caused by the corrosion reaction W(DISS), and acceleratory contribution due to the presence of passivating oxide film W(ACC). The relative fraction of the acceleratory contribution increased with increasing applied potential up to 200 mV(SCE), and then decreased. In order to investigate the role of the passivating oxide film in the corrosive wear process, potentiokinetic measurements, inductively coupled plasma spectroscopy, and scanning electron microscopy were carried out. From the results of such experiments, the variations of corrosive wear rate and acceleratory contribution associated with the applied potential are discussed in terms of competing of the corrosion reaction and compositional change in the passivating oxide film.